Generally, conventional cable television (CATV) systems operate to provide a full service distribution network for distributing combined national and local video and audio programming to customer locations. Such CATV systems collect signals from a variety of national and local service providers and television stations for rebroadcast over a dedicated coaxial cable distribution network. Conventional CATV systems typically include a headend office for receiving and rebroadcasting of the various service provider signals.
While such full service networks have operated to distribute signals to the customer locations, to date, such networks have struggled to provide the latest in customer services and features. These services and features often require speed, signal quality, and network flexibility that is simply not capable with existing full service networks.
In addition, available video headend architectures have been designed to include digital compression technology. In such an arrangement, nationally distributed programming is received locally through the use of satellite integrated receiver decoder/demodulators (IRDs) which demodulate, descramble, and in some cases decompress the programming to produce an NTSC analog, composite, or digital output. This output is in turn fed through distribution amplifiers and switcher/routers (used to provide redundancy and monitoring) and forwarded to respective encoders such as a DiviCom encoder for MPEG-2 compression. The various encoded streams are multiplexed together into a Multi-Program Transport Stream (MPTS) by a remultiplexer, and then forwarded onward for distribution to the cable customers. A system controller is used to construct the transport stream definition so that the remultiplexer is aware of which information from the various inputs, such as encoders, NVOD (Near Video-On-Demand) servers, etc., needs to be extracted and combined into the MPTS. The controller also monitors and controls (such as when combined with automated redundancy) the various equipment in the headend.
However, as a result of lower prices and higher video quality, the use of digital (MPEG-2) compression in the distribution of programming is gaining market acceptance. For example, program providers such as HBO and Viewers Choice now provide an entire satellite transponder worth of compressed content. Since typical head architectures automatically decompress the source signals before passing the programming on to the customer, these architectures prevent the full realization of the benefits provided by digital compression.
Therefore a need exists for both a full service network architecture which can meet the growing and changing demands of the market, and an improved headend architecture capable of higher efficiency and quality of signal distribution, while being able to support IRDs that deliver previously compressed MPTS.